Release v0.3.0

User ID Agnostic Architecture

BREAKING CHANGES:
- Package now supports int, uuid, uuid_binary, ulid, ulid_binary User IDs
- Must configure LARABILL_USER_ID_TYPE for non-integer IDs

NEW FEATURES:
- MigrationHelper for agnostic foreign keys
- Auto-detection command: larabill:detect-user-id
- Multi-database support (MySQL, PostgreSQL, SQLite)

See CHANGELOG.md for full details and migration guide.